So my minecraft server has an economy plugin I've been working on. After battling a couple of days, I realised this is a common problem with Java that it won't unload the classes which are already loaded. So when I tried the plugin on a fresh server instance, it was working correct.
My question is how can I fix the original server? I tried deleting the updated JAR file from that server, ran and stopped the server as a guess that it'd remove the pre-loaded classes but instead that generated the files related to the previous version of plugin, even though the plugin's JAR wasn't in the directory.